Variable-speed-transmission mechanism



Oct. 9, -1928.

A." A. WIEDMAIER v VARIABLE SPEED TRANsMrssoN uEcHANrsu,

.3 Sheets-Sheet Filed June 6, 1927 NN www w .ff m

"x l ss Kl A Oct. 9, 1928. 1,681,075

A. A. WIEDMAIER VARIABLE SPEED TRANSMISSION EcHANISll lFiled June 6, 1927 5 Sheetsf-Sheet 2' l gnwntoc Kaya/)292;

Oct.` 9, 1928.

A. A. wlEDMAn-:R

vARIABLE SPEED TRANSMISSION MEQHANISM Fiied June e, 192# 3 Sheets-Sheet Patented Oct. 9, 1928.

UNITED STATES 1,687,075 Pari-iurv OFFICE.

ARTHUR WIEDMAIER, OF CLEVELAND, OHIO, ASSIGNOR F ONE-HALF TO LLOYD M. FIELD, OF CLEVELAND, OHIO.

VARIABLE-SPEED-TRANSMISSION MECHANIS.

Application led. June 6, 1927. Serial No. 196,727. i

This invention relates to variable speed transmission mechanisms of that type associated with the rear axle assembly ofa motor driven vehicle, and more particularly to a reduction gear mechanism which is built about a beveled gear differential mechanism in a rear axle housing.

My-invention aims to provide asimple, durable and compact variable speed transmission wherein clutches are associated with reduction gears and dierential casing for obtaining intermediate and low speeds, one

of said clutches serving asa conditioning clutch by which the other clutch is operative for reduced speeds. v

My invention further aims to provide a differential mechanism in which reduction gears are embodied with a Jfull floating spider ailfording a bearing for differential andreduction pinions which cooperate with the differential and reduction gears in providing ,reduced speeds for rea-r axle shafts.

M y invention includes certain manufacturing reinements that are of an advantageous nature and my various' im rove ments will be hereinafter specificsal y described and then claimed.

Reference will now be had to the drawing, wherein Figure 1 is a longitudinal horizontal sectional view of a variable speed transmission showing the conditioning and reduction clutches in neutral position;

Fig. 2 is a diagrammatic view of the transmission mechanism showing the clutches adjusted :tor a maximum reduction or low speed; y

Fig. 3 is a similar view showing the clutches adjusted for an intermediate reduction or intermediate speed.

Fig. 4' is a similar view showing the clutches adjusted for full gear ratio or high speed;

tional bearing structure 4 for the inner end non-rotatably ixed;

structures 39.

and its assembly of pinions,

of the drive shaft 4,' so that this end of the drive shaft ma safely support a small beveled gear whee 5.

The detachable plate 2 is provided with supports 6 and 9 for anti-frictional bearin lstructures 7 and 8, the former being retaine in the support 6 b a retaining ring 10 and the latter retaine in the support 9 by a fixed element 11 and a retaining ring 12. The fixed element may be keyed or otherwise non-rotatably mounted in the support 9.

Journaled inthe anti-frictional bearing structures 7 and 8 are the hub portions 13 and 14 of end plates 15 and 16 respectively forming part of a differential easing 17 provided with a large beveled gear Awheel 18 meshing with ythe small beveled gear wheel of the drive shaft 4.

Mounted in' the differential casing end late is an anti-frictional roller bearing 19 for the hub portion 20 of an intermediate speed gear 21. Mounted in the hub portion 20 of this intermediate speed gea-r 21 is an anti-frictional roller bearing 22 for the hub portion 23 of a low speed gear 24. Mounted in the hub portion 23 of the low lspeed gear 24 is an anti-frictional roller bearing 25 for the hub port-ion 26 of a differential gear 27. The gears 21, 24 and 27 are in nested relationconcentrically-of one' another and about a rear axle shaft 28 on which the differential gear 27 is keyed or non-rotatably ixed.

Mounted inthe differential casing end plate 16 is an anti-frictional roller bearing 29 for the hub port-ion 30 of a speed gear 31, and mounted in the hub portion 30 of i this gear is an anti-frictional roller bearing 32 for the hub portion 33 of aditi'erential gear 34. The gears 31 and 34 are concentric of each other about a rear axle shaft 35 on which the differential gear 34 is keyed or The rear axle shafts 35 and 28 longitudinally aline substantially t axially of the rear axle housing .1 and are adapted for driving ground engaging Wheels of a vehicle.

In the differential casing 17 is a s ider 36 having its arms 37 provided with di erential pinions 38 and compound speed pinions 39, the latter being operatively held rela-tive to tlie spider arms 37 by anti-frictional roller I have deemed it only necessary to illustrate one of the spider arms 37 and since the spider 36 has no bearing on the differential loo l @il casing 17, it may be considered as full floating. However, in carrying out part ot the usual practice olf arranging a. spider between the ditlerential gears 27 and 34, the confronting ends or the rear axle shafts 28 and 35 may extendinto'the spider 36, 'lhe inner ends of the rear axle shafts are adequately supported through the various dillere'ntial and speed gears and the diderential casing end plates relative to the rear axle housing, and it is obvio-us that there may be other bearings in the housing tor the rear axle shafts, which bearings ll have deemed unnecessary to illustrate.

A slidable toothed clutch member 40 is splined or otherwise slidably keyed on the hub portion 30 of the speed gear 31 to rotate therewith and said clutch. member is shiittable in two directions by a conventional form oi' clutch shitting device generally designated 41. llhe clutch member 40 is employed 'lor conditioning purposes and as such is engageable, when moved in one direction with a clutch member 42 tormingpart of the lined element 1l, .and when shitted in an opposite direction is engageable with a clutch member 43 Aorming part of the hub portion 14 of the diderential casing end plate 16. This conditioning clutch will be hereinafter considered when describing the operation of the transmission mechanism,

fr reduction clutch 44 is slidably mounted in the' hub portion 13 ot the differential c asing end plate 15, said clutch member being splined or slidably lreyed for rotationvvith the hub portion 13 oit the end plate 15. A con` ventional torni of clutch shitting device 45 he employed tor shitting the clutch member 44.

Complemental to the clutch member 44 are clutch members 46 and 47, the ilormer being a part 'ot the hub portion 20 oit the intermediate speed gear 21, and the `latter a part of the hub portion 23 ot the low speed gear 24. The reduction clutch 44 can be shifted to establish rotative continuity between the dit- "t'erential casing 17 and the intermediate speed gear 21 or between the dilierential casing 17 and 'the low speed gear 24.

Operation The-transmission mechanism, as shown in Fig. 1, is in what may be considered a neutral condition, that is, the conditioning clutch 40 is out of engagement with its complemental clutch members 42 and 43. The reduction clutch 44 is out of engagement with its complemental clutch members 46 and 47, therefore the differential casing 17 may be driven Withoutimparting rotation to the rear axle'shafts 28 and 35.-

lFor a maximum reduction or low speed the conditioning clutch 4 0 is shifted into engagement With the clutch member 42 of the fixed v element 11, whereby the speed gear 31 is held stationary. rllhe reduction clutch 44 is shittment with gear 24 there is a tull .La meenam.

speed 'gear 24, so that the ldriven differential speed to the spider structure which through' the diderential pinions 38 and the differential gears 27 and 34 imparts rotation to the rear axle shafts 28 and 35. rlhese shafts, of course,

have the usual dilerential action When necessary.

An intermediate speed or an vintermediate reduction is attained by leaving the clutch 40 in engagement with the clutch member 42 of the xedelementll, and shifting the clutch 44 into engagement with the clutch member 46 of the intermediate speed gear 21. As this intermediate speed gear is driven from the d-iderential casing 17 thecompound pinion 39 with which it meshes will roll on the stationary speed gear 31 and provide a different speed trom that. diagrammatically illustrated in Fig. 2. Y

.A high speed is attained by placing the reduction clutch 44 in mesh With clutch member 47 and shifting the conditioning clutch 40 into engagement- With the clutch member 43 of the differential casing `end plate 16. 'llhis means that the controlled gear 31 will be driven by the differential casing 17 and through the medium of the compound pinion 39 drive thespider at a greater speed than it it Were rolling on a stationary gear.

'lhe above operations may be summarized as follows:

When clutch 40 is in engagement With ixed element 11, there is a maximum reduction When clutch 44 engages gear 24, and an intermediate reduction when clutch 44 engages gear 21. 4

When clutch 40 is in engagement with the differential casing 17 and clutch 44 in engage'- gear ratio and no reduction. f

When clutch 44 is in engagement with gear 21 there is an intermediate reduction only when clutch 40 is engaged with the fixed element 11, and when clutch 44 is in engagement with gear 24 there lis a maximum reduction only when clutch 44 is in engagement With the fixed element 11.

ln the modified clutch construction4 shown in Figures 5 and 6, the end plate 15 is formed With a sleeve 15a surrounding` and spaced from the axle 28 and having one end supported in the casing l through the medium ot ballbearings 7'. ln the face of the end plate are formed annular grooves 21a and 24 which loosely receive the intermediate speed gear 21 and low speed gear 24 respe/ctively.

A spindle 50 is journaled in the casing at right anglesv to the axle 28 and may be turned by linkage 51 vextending to a point Within reach of the operator. Pin-s 52 and 53 are slidably mountedl in the end plate 15- and are adapted to enter pockets 54 and 55 formed in the gears 21 and 24 respectively. lhe pins are provided in pairs as clearly shown in Figure 6, the voutermost member of each pair being associated with the gear 21 and the inner member With the gear 24. At each pair of pins the end plate 15 is formed with a pair of ears 56 between which is pivoted a rocker arm '57 having enlargements 58 and 59 formed at opposite sides of the pivot point and received in recesses 60 and 61 cut in the pins 52 and lrespectively. The enlargement 61 is at one of ,the extremities of the rocker arm, and the other extremity (52 is extended beyond the other enlargement 58.

A ring 63 of double channel formation engages the extremities 62 of the rocker arms. To the spindle 5G is fixed a yoke 64 provided at its ends with pins 65 entering the outer channel of the ring as shown more clearly in Figure 6. actuation of the linkage 51 Will move the ring and consequently the rocker arms and pins in one direction or the other.

The length of the pins and the amplitude of the movement-s of the rocker arms are such that the pins may secure only one of the gears 21and 24 at a time to the end plate 15. Also, a neutral position may be obtained, wherein neither gear is locked to the plate. The operation of the device in its various adjustments is similar to the operation of the construction shown in Figure 1.

l attach considerable importance to the fact that a full gear ratio isattained by the clutch 40 enfraging the differential casing 17 regardless o the position of the clutch 44, which is a reduction clutch serving the gears 21 and 24 and the speed of these gears is conditioned by the clutch 40 holding the speed gear 31 stationary. Furthermore and from a manufacturing standpoint the spider structure is an assembled unit that may be readily assembled between the nested concentric gears and with 'these elements supported from the plate 2 of the rear .axle housing, it

is an easy matter to remove the differential and reduction gear mechanism after the inner ends of the axle shafts have been Withdrawn. All of this contributes to a very compact easily assembled mechanism and While l have shown a preferred embodiment of my invention, it is to be understood that the structural elements are susceptible of Such changes as are permissible by the appended claims.

What l claim is 1. ln a variable speed transmission mechanism, a driven differential casing, axle shafts extending therein, differential gears operativelyconnectingsaidaxleshafts,changespeed gears rotatable about the differential gears in speed gears and adapted to establish low vsaid casing, means operatively connecting said change speed gears to said diierential .Y gears, a conditioning clutch adapted to eonnect one of said speed gears to Said diderential casing for high speed and fix thesame change speed gear for other s eeds, and a reduction clutch driven by sai differential casing and adapted to be connected to other of said change speed gears to establish lovv and intermediate speeds.

2. A'variable speed transmission mechanism as called for in claim V1`Wherein said connecting means comprises a spider rotatable about said shaft and having arms, and gears on said arms meshing with said change speed gears and certain of said vdiderential gears.

3. ln a variable speed transmission mechanism, a driven differential casing, 4arie shaft-s extending therein, dierential gears and pinions operatively connecting said axle shafts, change speed gearsjournaled in said differential casing and affording bearings forthe differential gears, a fixed element, a conditioning clutch adapted to either connect one of said change speed lears to said differential casing or to said xed element, and a reduction clutch rotative with said differential casing and adapted to connect one or the other of said change speed gears for rotation with said differential'casing when said conditioning clutch engages said fixed element.

4. n a variable speed transmission mechanism, a driven differential casing, axle shafts extending therein, a differential gear mechanism including a spider for operatively connecting said axle shafts, change speed gears nested about the gears of the diierential mechanism, a com ound reduction'pinion 1 carried by the spidero said dierential mechanism, and meshing With said change speed gears, a conditioning hclutch adapted to condition one of said change speed'gears for high speed and other speeds, and a reduction clutch rotatable with said differential casing and engageable with other 'of said chang an intermediate speeds when said conditioning clutch is in position for holding its change speed-gear for such speeds. l

5. A variable speed mechanism as called for in claim 4, wherein said clutches are slid-- able co-axially of each other and said conditioning clutch adapted for rotation with one of said speed gears.

6. In a variable speed mechanism, a driven dierential casing, axle shafts extending therein, di'erential gears and pinions operatively connecting said axle shafts, a lined element, lov:7 and intermediate speed gears at one side of said differential casing, a speed gear at the opposite side of' said diderential casing, a conditioning clutch rotatable with said speed gear and adapted to either tix said gear to said differential casing for high speed or to said fixed element for low and intermediate speeds, a conditioning clutch rotat-l` able With said dierential casing and engageable withl either said low or intermediate speed gear toestablish either speed When said speedl gear is conditioned by its clutch engaging said tixed element, and a compound pinion associated with said di'erential pinions and having elements meshing Wit-h said speed gears. v

7. Variable speed transmission mechanism as called for in claim 6, wherein a spider forms part of the dierential gear mechanism and supports said compound gear in spaced relation to said dierential casing.,

manera 8. ln a variable speed transmission mechanism, fixed and rotatable elements, a pair of axle shafts, change speed gears rotatable about` said shafts, means for selectively connect-ing said gears to said fixed and rotatable elements, differential gears mounted on said shafts, a spider rotatable about said axle shafts and having arms, differential gears mounted on said arms in mesh with said firstnamed dii'erential gears a compound gear on .ARTHUR a. WIEDMmR. 

